unperplex.js

#!js
0,function(stream){
  var lines = [], line;
  while((line = stream.readLine()) !== null) lines.push(line);
  var code = lines.join('\n');
  if(!code) return print('usage: js {this} < perplexing.js > unperplexed.js');
  code = (Function(code.replace(/^#!.*\n?/, '')).toString()
          .replace(/^\s*function.*\s+/, '')
          .replace(/^ {4}((?:  )*)\1/mg, '$1') // halving indentation
          .replace(/\s+\}\s*$/, ''));
  print(code);
  return code;
}(typeof java === 'undefined'
  ? {readLine: readline}
  : new java.io.BufferedReader(
    new java.io.InputStreamReader(java.lang.System['in'])));